SPONGE
Sigmadocia caerulea
Hechtel, 1965
Blue Caribbean sponge
Phylum
Class
Subclass
Order
Family
Porifera
Demospongiae
Ceractinomorpha
Haplosclerida
Chalinidae
Photo by R. DeFelice
DESCRIPTION
Growth Form
Thickly encrusting or massive (irregular, solid form)
sponge with raised thick-walled volcano-shaped
oscules, up to several centimeters in height.
Color
Exterior is pale blue-green, interior color is a dirty
yellow.
Texture and Surface Features
Specimens are soft and easily torn. Surface is even,
somewhat smooth, like fine sandpaper.
HABITAT
In the Hawaiian Islands, S. caerulea is mainly restricted
to shallow-water fouling communities (i.e. pier pilings,
floating docks) of the major harbors on Oahu or
associated disturbed habitats (i.e. dredged channels and
artificial lagoons). It is also found on the roots of the
nonindigenous Red Mangrove, Rhizophora mangle,
native to Florida, West Indies, and South America,
which is abundant in Pearl Harbor and Keehi Lagoon.
In Kaneohe Bay, S. caerulea is found on patch reefs in
southeast corner of the bay as well as the fouling
community on Coconut Island floating docks.
DISTRIBUTION
Spicules
Megascleres: bent oxeas (170-230 µm). Microscleres:
sharply curved C-shaped sigmas (25 µm).
HAWAIIAN ISLANDS
Oahu – Pearl Harbor, Honolulu Harbor, Keehi Lagoon,
Kewalo Basin, Ala Wai Harbor, and Kaneohe Bay.
Kauai – Nawiliwili Harbor.
Midway Atoll – main harbor.
MECHANISM
oxea
sigma
Spicules of Sigmadocia caerulea.
OF I NTRODUCTION
Unintentional introduction, most likely as fouling on
ships’ hull.
NATIVE RANGE
Caribbean or Eastern Pacific (Panama)
PRESENT DISTRIBUTION
© Hawaii Biological Survey 2001
Caribbean, eastern Pacific at Panama, main Hawaiian
Islands, and Guam.
B-1
Sigmadocia caerulea
IMPACT
Fouling organism. Ecological impact unstudied, but
probably some competition for space with native
species.
ECOLOGY
Feeding
Like all shallow-water sponges, S. caerulea is a filter
feeder, continuously circulating water through their
bodies. Microscopic food particles are removed from
water by specialized collar cells. Digestion is intracellular.
Reproduction
S. caerulea is capable of asexual reproduction by
fragmentation of the adult. Details regarding sexual
reproduction of this species are unstudied. Many
sponges are sequentially hermaphroditic. These
sponges reproduce sexually by capturing sperm that has
been released into the water column by adjacent
individuals and transporting it to an awaiting egg deep
within the sponges aquiferous system. The embryo
may be released shortly after fertilization or held for
further development. The embryo released is typically
a motile larva, which after a time in the plankton,
settles to the bottom and develops into a young sponge.
REMARKS
This sponge is considered to be a recently unintentionally introduced species due to its sudden appearance in
the islands and widespread disjunct geographic distribution (Caribbean and Hawaiian Islands). De
Laubenfels (1950) and Bergquist (1967) both conducted sponge surveys on the floating docks on Coconut Island in Kaneohe Bay, Oahu where S. caerulea is
now abundant. It is unlikely that this conspicuous
species was present but overlooked by these researchers.
B-2
Sigmadocia caerulea from the Caribbean, was first
described from Jamaica by Hechtel (1965). He reports
this species as common on pilings and mangrove roots,
as well as in a sandy turtle grass bed. Van Soest (1980)
reports the species from mangrove roots and intertidal
rocks in the Caribbean. Wulff (1996) also collected S.
caerulea from mangrove roots in the Caribbean, but
noted that eastern Pacific specimens were only found
associated with the bases of branching pocilloporid
corals.
Introduction to Hawaii was most likely by means of
fouling on a ship’s hull. S. caerulea was previously
only known from the Caribbean and the eastern Pacific
at Panama. The initial inoculation point was probably
Honolulu or Pearl Harbor on Oahu. It now also occurs
in the main harbor on Kauai, but was not found on any
other neighboring main islands when surveys were
conducted in 1997. S. caerulea was recently transported from Pearl Harbor to Guam on the hull of a
floating dry dock. It remains to be seen whether this
sponge will become established there.
REFERENCES
Bergquist, P. R. 1967. Additions to the sponge fauna of
the Hawaiian Islands. Micronesica. 3: 159-174.
Hechtel, G. J. 1965. A systematic study of the
Demospongiae of Port Royal, Jamaica. Peabody Mus.
Nat. Hist. Bull. 20: 1-103.
Laubenfels, M. W. de. 1950. The sponges of Kaneohe
Bay, Oahu. Pac. Sci. 4(1): 3-36.
Soest, R.W.M. van. 1980. Marine sponges from Curacao
and other Caribbean localities. Part II. Haplosclerida.
Stud. Fauna Curacao. 62(191): 1-173.
Wulff, J. 1996. Do the same species of sponges live on
both sides of the isthmus of Panama? in Recent Advances in Sponge Biodiversity and Inventory and
Documentation, Bull. Inst. Royal Sci. Nat. Belgique.
66: 165-173.
© Hawaii Biological Survey 2001